[exim] domainkeys - signall = 0, no point in using DK?

I'm playing with domainkeys support in exim. My setup is:

rcpt acl:
  warn    control = dk_verify

data acl:
   warn message = DomainKeys-Status: $dk_status
           !condition = ${if eq{$dk_status}{}{1}{0}}
           log_message = DK status: $dk_status testing: $dk_testing signall: 
$dk_signsall
   deny message = DomainKeys signature did not verify.
      !condition = ${if eq{$dk_status}{}{1}{0}}
      !condition = $dk_testing
      condition = $dk_signsall
      condition = ${if eq{$dk_status}{bad}{1}{0}}

2005-06-25 17:36:13 1DmChZ-0000GT-9k H=(wproxy.gmail.com) [64.233.184.197]
Warning: DK status: good testing: 0 signall: 0
2005-06-25 17:36:15 1DmChb-0000GY-4o H=(imail3.gazeta.pl) [193.42.231.137]
Warning: DK status: bad testing: 0 signall: 0

It seems that DomainKeys isn't really usable as no one uses signall = 1 and
denying messages when signall=0 is risky if I understand meaning of signall
correctly.

Is there any point in using DK now?

-- 
Arkadiusz Miśkiewicz                    PLD/Linux Team
http://www.t17.ds.pwr.wroc.pl/~misiek/  http://ftp.pld-linux.org/